Machine tool components such as heads, carriages, tail stocks, tool slides and the like are mounted upon guides and ways for major adjustment, and minor adjustment is often accomplished by threaded screws and elements, shims and the like. It is often desirable to make minor adjustments in slides, work holders, tool holders, etc. to compensate for misalignment, tool wear, out-of-round relationships, and the like, and by the use of threaded fasteners, set screws, shims, etc., minute dimensional adjustments of the nature of tenths of hundredths of a thousandth of an inch are difficult to uniformly achieve. Such small dimensional adjustments are time consuming, haphazardly achieved by trial and error, and require high skills on the part of the machine tool operator.
An object of the invention is to provide an incremental fine adjustment for machine tool components wherein very accurate adjustments may be quickly achieved.
A further object of the invention is to provide a fine adjustment for machine tool components wherein the rigidity of the components is not affected by the adjustment means, and wherein only small forces are necessary to achieve the adjustment.
Another object of the invention is to provide a machine tool component adjustment utilizing wedge surfaces wherein minimum frictional resistance exists at the wedge surfaces minimizing power requirements for adjustment.
An additional object of the invention is to provide adjustment means for machine tools wherein adjustment may be readily and quickly made of minute character and yet rigidity is maintained preventing chattering and vibration during machining.
In the practice of the invention a machine tool component such as a head, spindle, carriage, slide, or the like is mounted upon a frame, usually upon conventional ways and guides. The component to be adjusted in accord with the practice of the invention includes wedge surfaces in engagement with a wedge longitudinally adjusted by an incremental motor. Adjustment of the wedge imposes a force upon the machine tool component to produce the desired adjustment.
Anti-friction bearing means are interposed between the adjustable wedge and the machine tool component and frame to minimize the energy required to move the wedge. The wedge is preferably adjusted by means of an electric indexable inching motor rotating a threaded shaft, and operation of the motor can be easily controlled to produce movements of one ten thousandths of an inch, or less.
The force imposed upon the adjusted component is resisted by high pressure compression biasing means capable of accommodating the movement produced by the wedge, yet sufficient to produce a biasing force high enough to prevent chatter and vibration even under heavy machining conditions. In the disclosed embodiment this biasing means is in the form of a plurality of Belleville or tapered disc springs under adjustable compression.
By operation of the electric inching motor, the wedge is longitudinally positioned to vary the spacing between the adjusted head, slide, carriage, etc., and the frame, and the biasing means will maintain the wedge under a predetermined compressive force eliminating any "play" or clearance assuring accurate, vibration-free adjustment. No special skills are required by the operator in that the degree of adjustment achieved may be readily observed by means of conventional gauges, and by reversing the direction of the inching motor the machine tool component may be very quickly and very accurately positioned in either direction to compensate for tool wear or other slight dimensional changes as required.